The present invention relates to a method for making wearable articles such as disposable diapers, disposable diaper covers or the like and, more particularly, to a method for forming side flaps on opposite sides of such articles and for incorporating elastic members into these side flaps to provide a fitness around the wearer's legs.
It is well known, for example, in disposable diaper, to form the side flaps of high flexibility on the opposite sides thereof and to incorporate the elastic members into said side flaps to provide the desired fitness around the wearer's legs so that this disposable diaper may be assembled in the form of pants in actual use, and such disposable diaper is the one which has been most commonly used in practice.
The side flaps in such diaper of the prior art generally comprise the portions of the topsheet and the backsheet extending from opposite sides of the absorbent core which has top and bottom sides covered with said topsheet and said backsheet, respectively. In other words, the respective sheets thus forming together the side flaps are respectively continuous.
However, formation of the side flaps simply from the topsheet and the backsheet in the articles such as disposable diapers which must be mass-produced at a high rate from the economical viewpoint would be encountered by various problems as following.
(a) It is impossible to form the side flaps from material which is different from the topsheet and/or the backsheet, for example, material being superior in its air-permeability, to said backsheet so as to improve an effect for preventing the interior of the articles from being steamed;
(b) When it is desired to provide said side flaps with a specific structure so as to insure that the side flaps may come in close contact around the wearer's legs in actual use of the article and thereby perfectly block excretion, it is difficult in practice to realize such structure on the production line simultaneously of formation of main bodies of the individual articles. Even if it is possible to do so, such manner of operation is not suitable for the disposable articles which require a high speed mass-production from the economical viewpoint; and
(c) Also when it is desired to vary factors such as the width of each side flap and the distance between the opposite elastic members selectively in the front area and the rear area of the article, the inconvenience similar to that as set forth in the precedent paragraph (b).
Accordingly, it is an essential object of this invention to provide an improved method for making wearable articles such as disposable diapers allowing the above-mentioned problems to be effectively solved by forming a part of the side flaps separately of the main body of each article and then joining this part to said main body on the production line.